Impact of Age on Surgical and Oncologic Outcomes After Colorectal Cancer Resection in Selected Patients Undergoing Primary Anastomosis: A Retrospective Propensity-Matched Cohort Study

Background: The impact of age on perioperative morbidity and long-term oncologic outcomes in colorectal cancer remains controversial. Although aging is linked to greater comorbidity and functional decline, advances in perioperative care have challenged the idea that older patients have worse outcomes. This study evaluated surgical and oncologic results in patients aged ≥ 75 years compared with younger individuals. Methods: We conducted a retrospective cohort study including patients who underwent colorectal resection with primary anastomosis between 2015 and 2022. Patients were grouped by age (< 75 vs. ≥ 75 years) and matched 1:1 using propensity scores based on preoperative clinical and tumor-related variables. Major complications (Clavien–Dindo grade ≥ III) were analyzed using logistic regression, and OS and RFS were assessed using Kaplan–Meier curves and Cox proportional hazards models. Results: Of 651 eligible patients, 272 were included in the matched cohort. No statistically significant differences were found between age groups in hospital stay (4.5 vs. 4.0 days; p = 0.270), reintervention (13.2% vs. 8.8%; p = 0.333), major complications (14.0% vs. 8.8%; p = 0.252), or 30-day perioperative mortality (3.7% vs. 0.7%; p = 0.216), although perioperative mortality was numerically higher among patients aged ≥ 75 years. Age ≥ 75 years was not significantly associated with major complications in multivariable analysis (OR 1.73; 95% CI 0.79–3.94). Five-year OS and RFS also did not differ significantly between groups. Conclusion: Older age was not associated with statistically significant differences in major complications or long-term oncologic outcomes in this matched cohort. However, clinically meaningful differences, particularly in short-term perioperative risk, cannot be excluded. Chronological age alone should not preclude curative-intent surgery.